What are the factors used to determine whether a person committed a first-degree murder?

People v. San Nicolas (2004) 34 Cal.4th 614, 658, 21 Cal.Rptr.3d 612, 101 P.3d 509 ( San Nicolas ).) These factors are simply a "framework to assist reviewing courts in assessing whether the evidence supports an inference that the killing resulted from preexisting reflection and weighing of considerations," and do "not refashion the elements of first degree murder or alter the substantive law of murder in any way." ( People v. Thomas (1992) 2 Cal.4th 489, 517, 7 Cal.Rptr.2d 199, 828 P.2d 101.)